Process of preparing 2-methyl-3-aminobenzotrifluoride

Abstract

2-methyl-3-aminobenzo-trifluoride is prepared with high yields and high productivity by first halogenating o-trifluoromethylbenzalhalide, then secondly hydrogenating 2-trifluoromethyl-4-halogeno-benzalhalide formed by the first reaction, then thirdly nitrating 2-methyl-monohalogenobenzotrifluoride formed by the second reaction, and then fourthly hydrogenating 2-methyl-3-nitro-5-halogenobenzotrifluoride formed by the third reaction.

What is claimed is: 
     
       1. A process of preparing a 2-methyl-3-aminobenzotrifluoride, comprising the steps of: (a) halogenating o-trifluoromethylbenzalhalide to form a 2-trifluoromethyl-4-halogenobenzalhalide;   (b) hydrogenating said 2-trifluoromethyl-4-halogenobenzalhalide to form a 2-methyl-5-monohalogenobenzotrifluoride;   (c) nitrating said 2-methyl-5-monohalogenobenzotrifluoride to form a 2-methyl-3-nitro-5-halogenobenzotrifluoride; and   (d) hydrogenating said 2-methyl-3-nitro-5-halogenobenzotrifluoride to form said 2-methyl-3aminobenzotrifluoride.   
     
     
       2. A process according to claim 1, wherein in the step (a) said o-trifluoromethylbenzalhalide is halogenated with a halogen in the presence of a catalyst. 
     
     
       3. A process according to claim 1, wherein said o-trifluoromethylbenzalhalide is selected from the group consisting of o-trifluoromethylbenzalchloride, o-trifluoromethylbenzalbromide and o-trifluoromethylbenzaliodide. 
     
     
       4. A process according to claim 1, wherein said o-trifluoromethylbenzalhalide is o-trifluoromethylbenzalchloride. 
     
     
       5. A process according to claim 2, wherein said halogen is selected from the group consisting of chlorine and bromine. 
     
     
       6. A process according to claim 2, wherein said halogen is chlorine. 
     
     
       7. A process according to claim 2, wherein said catalyst is selected from the group consisting of ferric chloride, ferric bromide, aluminum chloride, aluminum bromide and antimony pentachloride. 
     
     
       8. A process according to claim 1, wherein the halogenation from the step (a) is carried out at a temperature ranging from 60° to 100° C. 
     
     
       9. A process according to claim 1, wherein in the step (b) said 2-trifluoromethyl-4-halogenobenzalhalide is hydrogenated with hydrogen in the presence of a metal-carried catalyst and an optional basic substance. 
     
     
       10. A process according to claim 9, wherein said metal-carried catalyst has a metal carried by a carrier, said metal being selected from the group consisting of Pd, Pt, Rh and Ni, said carrier being selected from the group consisting of active carbon, alumina, zeolite and silica-alumina. 
     
     
       11. A process according to claim 9, wherein said basic substance is selected from the group consisting of a hydroxide of an alkali metal or of an alkali earth metal, a carbonate of an alkali metal or of an alkali earth metal, an acetate of an alkali metal or of an alkali earth metal, a borate of an alkali metal or of an alkali earth metal, and a phosphate of an alkali metal or of an alkali earth metal. 
     
     
       12. A process according to claim 11, wherein said basic substance is selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, sodium acetate, potassium acetate, sodium borate, potassium borate, disodium phosphate and trisodium phosphate. 
     
     
       13. A process according to claim 1, wherein the hydrogenation in the step (b) is carried out at a temperature ranging from 0° to 100 ° C. 
     
     
       14. A process according to claim 1, wherein in the step (c) said 2-methylmonohalogenobenzotrifluoride is nitrated with nitric acid in the presence of sulfuric acid. 
     
     
       15. A process according to claim 14, wherein said nitric acid is selected from the group consisting of concentrated nitric acid and fuming nitric acid, and wherein said sulfuric acid is selected from the group consisting of concentrated sulfuric acid, fuming sulfuric acid and anhydrous sulfuric acid. 
     
     
       16. A process according to claim 1, wherein the nitration in the step(c) is carried out at a temperature ranging from 0° to 80° C. 
     
     
       17. A process according to claim 1, wherein in the step (d) said 2-methyl-3-nitro-5-halogenobenzotrifluoride is hydrogenated with hydrogen in the presence of a metal-carried catalyst and an optional basic substance. 
     
     
       18. A process according to claim 1, Wherein the hydrogenation in the step (d) is carried out at a temperature ranging from 60° to 130° C.